Fluid operated control system



March 18, 1947. J s o FLUID OPERATED CONTROL SYSTEM Filed Jan. 14, 1944 4 Sheets-Sheet 1 AYEI/IENTOR axe 1 6 Z @ZMM?.

March 18, 1947. J, s o E 2,417,524

FLUID OPERATED CONTROL SYSTEM Filed Jan. 14, 1944 4 4 Sheets-Sheet .2

j g-Q J jam 0 05 er a 87 8% 7 v Jrrom EY March 18, 1947. J, J, SLQMER 2,417,524

' FLUID OPERATED CONTROL SYSTEM 1944 4 Sheets-Sheet 3 Filed Jan. 14,

. m P N 7. m1 .7 m 9 fl m J n N w 5 P. W r 4 P d 6 /Z m A I '10 a J M m March 18, 1947. SLQMER 2,417,524

FLUID OPERATED CONTROL SYSTEM Filed Jan. 14, 1944 4 Shets-Sheet 4 114 137 140 I9 I34 44 145 J J 1/3 5 1 J10 Patented Mar. 18, 1947 FLUID OPERATED CONTROL SYSTEM Joseph J. Slomer, Chicago, 111., assignor to Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Application January 14, 1944, Serial No. 518,245

12 Claims. (01. 172179) This invention relates to improvements in fluid operated control systems particularly adapted to control the electric circuits of motors used to propel mine locomotives.

Heretofore controllers of the fluid operated and mechanical and electrically operated types have been so arranged that upon overload of the motor circuit all of the contactors open at one time. This creates a heavy arc that cannot adequately be extinguished, and thus causes excessive burning of the contacts of the controller.

One of the principal objects of my present invention is to overcome this excessive arcing and burning of the contacts by providing a novel form of fluid operated controller for a motor circuit, having a fluid pressure release of a novel construction, electrically connected with the motor circuit, and so connected in the fluid control system as to release fluid therefrom upon overload of the electric circuit, in such a manner that the electric contacts, closing the electric circuit, will open step by step in a predetermined order.

Another object of my invention is to provide a novel and eflicient form of fluid release valve electrically connected in the motor circuit so as to release fluid from the system upon overload of the locomotive circuit.

Still another object of my invention is to provide a fluid operated controller including a novel form of control valve for supplying fluid to control opening and closing of the contactors at pressures increasing or decreasing step by step, to successively open or close the electrical contacts of the control system.

A further object of my invention is to provide a new and improved form of fluid control valve and fluid operated control system adapted to positively operate a plurality of devices in a regular sequence or order.

A prior application Serial No. 488,015, filed by William-W. Sloane on May 22, 1943, which is a division of application Serial No. 456,490, filed on August 28, 1942, which issued as Patent No. 2,383,894 on Aug. 28, 1945, relates to a fluid operated control system somewhat similar to that shown in my present invention. My present invention, however, differs from that disclosed in the prior application of William W. Sloane in the form of control valve for supplying fluid at pressures increasing or decreasing step by step, to operate the contactors for closing the electric circuit, and in the form of release means for releasing fluid under pressure from the system upon overload of the electric circuit.

Other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

Figure l is a diagrammatic view illustrating an electrical control circuit for the motors of an electrical device, such as a locomotive, and showing the fluid circuit for controlling operation thereof;

Figure 2 is a fragmentary plan view of a variable pressure control valve constructed in accordance with my invention, with certain parts of the valve broken away and certain other parts shown in horizontal section;

Figure 3 is a fragmentary view in side elevation of the valve shown in Figure 2, with certain parts broken away and certain other parts shown in longitudinal section;

Figure 4 is a detail horizontal sectional view taken through the valve illustrating certain details of the interlock for interlocking the variable pressure control valve with the valve for controlling reversal of the locomotive;

Figure 5 is an end view of the control valve with certain parts thereof shown in transverse section in order to show certain details of the Valve;

Figure 6 is a detail transverse sectional view of the valve showin certain details of the manually controllable emergency valve, for releasing fluid from the fluid pressure system;

Figure '7 is a transverse sectional view taken substantially along line 1-1 of Figure 2;

Figures 8 and 9 are enlarged detail sectional views of the variable pressure control valve, showing said control valve in closed and open positions respectively;

Figure 10 is a detail view of the control valve, showing certain details of the fluid connections thereto;

Figure 11 is a plan view of the release Valve with certain parts thereof shown in horizontal section; and

Figure 12 is a longitudinal sectional view taken through the valve shown in Figure 11.

For the purposes of illustrating my invention, Figure l of thedrawings diagrammatically shows an electric control circuit particularly adapted to control the simultaneous operation of a plurality of electric motors ll), l0, preferably the motors of a mine locomotive, together with a hydraulic control system arranged in accordance with my invention, for controlling the operation of the electrical contacts of this control circuit. Said motors are herein shown as being connected in parallel for simplicity, it being understood that 3 the electric control circuit may be so arranged as to connect said motors in series or in series parallel, or in any other desired manner. Starting and stopping of said motors is controlled by a plurality of fluid operated contactors 2, 3, 4, 5, 6, l and 8, contained in a suitable control box (not shown) and arranged to connect the motors to a main power line I! and to progressively cut sections of a resistance l2 into or out of the motor circuit.

A fluid pump l3, driven by an electric motor I4, is provided to supply pressure for the system. Said pump is supplied with fluid from a suitable tank, herein shown as being the low pressure side of an accumulator l5, by means of a pipe I6. Said accumulator serves as a fluid storage tank for the hydraulic system andmay be of any well known form, and is herein shown as including a tank I! having a cover l9. Said cover is provided with an inwardly extending cylindrical piston 20 extending within and opening into said tank and having a cylinder 2| slidably movable therealong. The inner end of said cylinder is closed and a flanged portion 25 of said cylinder is adapted to abut the inside of said cover l9 when said cylinder is in a retracted position. A pair of concentrically arranged compression springs 24 and 25 are interposed between the bottom of said tank and the inside of said flange 23 of said cylinder, to urge said cylinder into a retracted position.

A pipe 25 having a check valve 21 therein connects the pressure side of the pump l3 with the pressure side of the accumulator l5, to supply fluid under pressure thereto, to cause the cylinder 2| to move against the compression springs 24 and 25. The strength of the springs 24 and 25 is such as to accumulate fluid under pressure in said piston and cylinder and to supply fluid to the system at the required pressure whenever said fluid pump is out of operation, or at a pressure much higher than the capacity of said pump, where necessary.

The electric motor l4, which drives the pump I3, is controlled by a fluid operated switch 30. Said fluid operated switch may be of any well known form and is no part of my present invention, so is not herein shown or described in detail. Said switch is so arranged that when pressure in the pipe 25 reaches a predetermined value, a piston 3| in a cylinder 32 will be moved in a direction to open the electric circuit to the motor M, and when fluid pressure in said pipe drops below this predetermined value, said switch will close. The operating pressure at which said switch closes is determined by the springs 24 and 25 in the accumulator l5.

Av pressure pipe 36 leads from the high pres sure side of the accumulator l5, to a valve 31, for controlling operation of fluid brakes 38, 38 for the locomotive, in a well known manner. Said valve and brakes are no part of my present invention, so are not herein shown or described in detail.'

A pressure pipe 39 leads from the pressure pipe 36 to a variable pressure control valve indicated generally by reference character 40. Said variable pressure control valve is adapted to supply fluid under pressure to a distributor valve 4|, which is connected with the contactors to 8 inclusive for operating said distributor valve and said contactors in a predetermined order.

A control handle 62 on a vertical shaft 43 is provided to operate the variable pressure control valve 4|]. When said control handle is turned in one direction, fluid under pressure will be supplied to the distributor valve 4|, through a pipe 44, relief valve 55, and a pipe 56, at pressures progressively increasing step by step, and when said control handle is turned in an opposite direction, fluid will be released from said distributor valve at pressures progressively decreasing step by step, as will more clearly appear as this specification proceeds.

Fluid under pressure is admitted to the variable pressure control valve 40 through a poppet valve 21 mounted in a block or casing 35 for said variable pressure control valve. Said poppet valve is urged into a closed position by fluid entering said valve through the pipe 39 and by a coil spring 48. A rocking arm :29 is provided to open said poppet Valve. Said rocking arm is pivotally mounted on a vertical shaft 5| at one of its ends and has engagement with the projecting end of a stem of said valve, intermediate its ends. The opposite end of said rocking arm is bifurcated and has a roller 52 mounted between the furcations thereof on a pivotal pin 53 (see Figure 3). Said roller is adapted to engage a notch 54 in a notching cam 55, or any one of a plurality of spaced notches 55, 55 in said notching cam. When said roller is in engagement with the notch 54, said valve will be in an off position. When, however, aid roller rides out of said notch and int-o engagement with the notches 55, 55, effected by pivotal movement of said notching cam, said rocking arm will serve as an index, indexing the positions of the control handle 42 for certain predetermined pressures admitted to the pipe 44 and distributor valve 4| through the variable pressure control valve 40, it being understood that since the notches 56, 56

are not as deep as the notch 55, said valve will be in an on position when said roller is in engagement with said notches 55, 5S. Said index is herein shown as being formed integrally with a sleeve 51 keyed on the vertical shaft 43 and journaled in the casing 35 for the control valve.

As the control handle 42 is turned to an on position, to cause the roller 52 to ride out of the notch 54 and into the first notch 56, or into any one of the succeeding notches 55, 56, fluid under pressure will be admitted to the valve block through the poppet valve 41 to the variable pressure control valve til through a passageway 58, and will also be admitted to a passageway 59 leading to a manually operated emergency release valve 60 (see Figure l).

The release valve 55 is normally in a position, which in Figure 1 is shown as being an up position, to admit fluid under pressure to a reverse valve 6| in the valve casing 35, which controls reversal of the motors 0, i5. Said release valve, as herein shown, includes a land 62 on the inner or lower end of a piston 53. When said land and piston are in the position shown in Figures 1 and 6, fluid under pressure will pass through the barrel of said valve and out a passageway 64 leading to the reverse valve 6|. When the land 62 is depressed by the exertion of pressure on a hand grip 65 of said valve, a land 530 of said valve will block the passageway 59 to hold pressure in the line 39 so the hydraulic brakes 38 or other hydraulic devices of the locomotive may be operated. When said valve is in this depressed position, fluid pressure will be released from the reverse valve 6| to the return through the passageway 64, to and through a passageway 66 in the barrel of said valve and into the valve casing through a passageway 61. Fluid will then pass out of said casing through a passageway 68 leading to a return line 34, and

through said return line to the low pressure or tank side of the accumulator i5. A well known form of ball type spring-pressed detent 69 is provided to hold said control valve in either an open or closed position.

The reverse valve Bl includes a plunger slidably mounted in the valve casing 35. Said plunger, as herein shown, has an integrally formed land H at its lower end, an integrally formed land 72 spaced upwardly therefrom, and a third integrally formed land (3, spaced upwardly from said last mentioned land. The lands H and 12 are adapted to control the admission and release of fluid to the head end of a reversing cylinder 14, having a piston 15 slidably mounted therein. The lands l2 and 73 are adapted to control the admission and release of fluid to the piston rod end of said cylinder. Said piston 15 has a projecting piston rod I50 which has connection with an arm 15! extending from a reverse drum 18, for pivotally moving said reverse drum in one direction or another, to reverse the direction of the flow of current through the motors Ill, Hi and to reverse the direction of rotation. of said motors in a well known manner.

The reverse valve 6! is operated by a handle l'. on the upper end of a shaft 13 iournaled in the casing 35. Said vertical shaft has a spool-shaped lower portion l5, herein shown as being formed integral with its lower end, which has the plunger it of said reverse valve extending between the flanges thereof. A pin is mounted at its ends in the flanges of said spoolhaped portion and has slidable engagement with a slot 82 formed in said plunger ill. Said slot extends in an angular direction with respect to the longitudinal axis of said plunger from the center of said plunger towards the outer end thereof and opens to one side thereof. Thus, operation of said valve handle 17 to pivot the shaft '18 in one direction or another, Will slidably move said plunger along its longitudinal axis in the valve casing 35, to slidably move the lands 1 I, I2 and 13 in directions to cover and uncover certain ports in said valve casing, to supply fluid under pressure to one end or the other of the cylinder M, and to release it from the opposite end of said cylinder (see Fi ure 4) An interlocking means is provided to prevent operation of the reverse valve 6| when the control valve 40 is in an on position, and Vice versa. Said interlocking means, as herein shown, includes a plunger 83 slidably mounted in the valve casing for movement along its longitudinal axis in a direction transverse to the direction of movement of the plunger H! (see Figure 3). Balls 84, B4 abut opposite ends of said plunger 83. One of said balls 84 is adapted to ride in either one of a pair of grooves 85, 85 formed in the plunger 10. The opposite ball is adapted to engage a notch 86 formed in a disk 81, which is secured to the lower end of the control shaft 43. When said control shaft 43 is positioned so that the variable pressure valve is in an off position, one ball 84 will ride in the notch 85, formed in the disk 8?, permitting the opposite ball 84 to pass out of either of the grooves 85, 85 to permit free movement of the plunger 1!]. When said reverse valve is in an intermediate position the ball 84 engaging a notch of the disk 81 will lock said disk and the control shaft 43 from movement, and will prevent operation of the variable pressure control valve. When said reverse valve is in either a forward or reverse position, the associated ball 84 may fall into either one of the grooves 85,85

to permit the opposite ball 84 to ride out of the notch 86' and to permit operation of the control shaft 43, it being understood that upon operation of said control shaft, the outer periphery of the disk 81 will positively engage a ball 84 with either of the grooves 85, S5, to lock said plunger and reverse valve from movement.

When the plunger 19 of the reverse valve 5! is in the extreme position shown in Figure l, fluid under pressure will pass from the release valve til through the passageway 64 into the valve chamber. It will then pass through the space between the lands H and T2 of said valve, through a pressure pipe $8, to the head end of the cylinder M, to move the piston E5 in a direction which, as shown in Figure 1, is to the left. This will connect the motors ill, Iii to operate in one direction through the reverse drum 16, in a manner well known to those skilled in the art and not herein shown or described since it is no part of my present invention. Movement of said piston '53 within said cylinder to one extreme position or another will uncover a port 89 in said cylinder leading to a pressure pipe Bil. Said pressure pipe is connected with the distributor valve 4!, for supplying fluid under pressure to the contactors i to 8, inclusive, as the ports in said distributor valve leading to said contactors, are opened.

When the reverse valve BI is in the position just described, fluid will be released from the piston rod end of the cylinder", through a pipe 93 connected with said reverse valve. Fluid will pass through the chamber of said reverse valve between the lands T2 and 13 and out through the passageways 6'! and B8 to the return pipe 34.

When the plunger "H! has been moved in an opposite direction, by operation of the control handle H, the land 12 will be moved to a position to allow fluid to flow from the pressure passageway 54 through the pipe 93 to the piston rod end of the cylinder 14. This will move the land H to a position to connect the pipe 88 to the return through. a passageway 94, to release fluid pressure from the head end of the cylinder 1%. The application of fluid under pressure to the piston rod end. of said piston will turn the reverse drum in a direction to reverse the direction of rotation of the motors IO, [U in a well known manner, and will permit fluid pressure to pass through the cylinder l4 and out the port 89 and pipe 99, to the distributor valve 4 I.

The distributor valve 4|, diagrammatically illustrated in Figure 1, includes a cylindrical chamber 95 having a piston 96 movable therein. Said piston, as herein shown, has three spaced apart lands 97, S8 and 99, formed integrally therewith, the land 9'! being at the end of said piston, adjacent the inlet from the control pipe 45, so that fluid under pressure entering said valve from said pipe will move said piston against a coil spring I iii), interposed between the inner end of said chamber and the end of said piston opposite from the land 91.

A drain passageway lili is provided in the body of the chamber 95 and leads to the return pipe 34, to take care of any leakage of fluid past the lands er or 98. Another drain passageway N32 is provided in the body of said chamber. Said passage leads to the return pipe 34 and is provided to take care of any leakage of fluid past the land 99, and serves as a return for fluid released from the cylinders for operating the contactors I to 8, inclusive.

The pressure pipe 98 enters the distributor valve 4|, intermediate the ends thereof, at a point disposed adjacent the end of the land 99 which faces the land 98, when the spring I is extended, as in Figure-1. The lands 98 and 99 are so spaced that fluid under pressure will be supplied in the space between Said lands in all positions of the piston 99 in the cylindrical chamber 95. It should be noted that fluid admitted from the pipe 90 acts equally in opposite directions on the piston 99, in the space between the lands 98 and 99, so has no tendency to move said piston in the direction of its axis.

Pipes I93, I04, I05, I06, I01 and I08 are connected with suitable port openings or passageways in the chamber 95 at points disposed on the opposite side of the land 99 from the lands 9'! and 98, when the piston 99 is in an extreme ofi position. Said pipes are so arranged that the respective passageways connecting said pipes to the chamber 95 will be successively uncovered by the land 99, to progressively admit fluid under pressure from the pipe 90 to said pipes I03, I04, I05, I09, I01 and I08, upon movement of the piston 96 against the spring I00. Thus, as the piston 99 moves to successively uncover the passageways connected with the pipes I03 to I00, inclusive, fluid will be supplied to the motors for operating the contactors associated therewith, to close said contactors in a predetermined sequence. This will connect the motors in the main line circuit and cut the resistance I2 from the motor circuit step by step under control of the operator.

The strength of the spring I00 is such that the piston 99 will move a distance suflicient to cause the land 99 to open the passageway connected with the pipe I93 to fluid under pressure from the pipe 99, when fluid enters the end of the chamber 95 from the pipe 46 at a predetermined pressure, and will open the next passageway to fluid under pressure from the pipe 90, when fluid pressure on the land 9'! of said piston increases a predetermined amount, and so on, until all of the passageways are opened step by step. Upon reducing the fluid pressure entering the chamber 95 from the pipe 40, the spring I00 Will move the piston 96 in a reverse direction to successively close the passageways leading from the pipes I08, I91, I06, I05, I04 and I03, to pressure from the pipe 90 and to open said passageways to the drain I02, to release fluid under pressure from the contactors I to 8 inclusive in a predetermined order, and to disconnect the locomotive motors from the source of power.

Referring now in particular to the variable pressure control valve 40, which supplies fluid under pressure to the distributor valve 4I through the control line 44, relief valve 45, and control line it, at uniformly increasing or decreasing pressures, which change step by step for each port opening of said distributor valve as the control handle 42 of said valve is turned by the operator in one direction or another, said control valve is especially designed to maintain substantially the same pressures on the control line at the same position of the control handle, when said control handle and valve are turned in either an on or an off direction.

The control valve 40 is of the piston type having a piston I09 movable in a sleeve IIO, mounted in the valve casing 35. The variation in pressure resulting from said piston valve as it is admitting fluid from a lower to a higher pressure and from a higher to a lower pressure, is independent of pressure in the intake pressure line 53 and is due to the lap of the piston or to mechanical diiferences only. In order to reduce the lap of the piston and the mechanical differences to a minimum and thus reduce this variation in pressure for the same positions of the control handle as it is turned in an on or an off direction, said piston is provided with three lands III, H2 and H3, adapted to register with corresponding lands formed in the inner periphery of the sleeve -I I0, thus providing a multiple lap piston for controlling the admission of fluid to the control line 44. Said piston is drilled along its longitudinal axis from the left-hand end thereof for a portion of its length, and is cross drilled as indicated by reference character H4 at the left-hand end of the land III, to permit fluid under pressure to pass through the lefthand end of said piston, to and through the pressure line 44. A compression spring II5 extends within the drilled portion of said piston and tends to urge said piston in a direction to the right. Said piston is likewise provided with three lands I I8, H9 and I20 adjacent its righthand end, which control the discharge of fluid to the return. The provision of the multiple lands III, II2, and H3, and H9, H9 and I20, registering with corresponding lands formed in the inner periphery of the sleeve III}, makes it possible to reduce the lap of the piston so that pressure will be admitted or discharged by said piston with a very slight movement of said piston within the valve sleeve. This will reduce the inaccuracies of said valve due to mechanical differences, and will make the valve sufiiciently accurate to insure full and accurate opening and closing of the ports in the distributor valve 4| for the same positions on the control handle 42, when said control handle is being turned in an on or an oil direction.

The valve 40 is operated by a pair of spaced gears I23, I23, herein shown as being formed integrally with the control shaft 43. Said gears mesh with racks 524, I24 cut on spaced upper and lower inner ends I25, I 25 of a valve operating member I26 (see Figure 7). Said valve operating member is of a substantially C-shaped formation with the racks I24, I24 cut integrally with the upper and lower inner ends thereof, and has a sleeve I2? mounted therein and abutting a closed end I28 thereof (see Figure 3). Said closed end I28 of said valve operating member is slidably mounted on a hollow pilot I29. A hollow piston I30 is mounted on said pilot for movement therealcng and extends within said sleeve I21 and is concentrically spaced therefrom. Said hollow piston has an enlarged inner portion which fits snugly within and is secured at its inner end to an inwardly flanged portion of said sleeve I21, as by welding. A compression spring I33 extends within said valve operating member, between the inside of the sleeve I27 and the outside of the hollow piston I39, and is seated at one of its ends in said sleeve and piston. The opposite end of said compression spring abuts and is seated in a seat I34, freely mounted on the inner or righthand end of the piston I99. The connection between said seat and the valve piston is relatively loose, to avoid binding between said seat and piston and to cause an even pressure to be exerted on said piston by said spring at all times.

The pilot I29 is cross drilled adjacent its outer or right-hand end and the passageways formed by said cross drilled portion communicate with a passageway I35, leading to a passageway [36, communicating with an annular groove I31 formed in the outer periphery of the valve sleeve III). Said sleeve is cross drilled from said annular groove into the inside thereof, to permit fluid under pressure to enter said groove I31 through said cross drilled passageways and to pass through the passageways I35 and I35 to and through'the hollow pilot Fluid passing through said passageways may thus exert pressure on the inside of the hollow piston I33, to balance the pressure of the spring l33 so the control handle 42 can be operated with a minimum amount of effort and so said control valve will stay in any desired position for which it is set, without being held by the hand. At the same time pressure is exerted on the inside of the hollow piston I30, fluid under pressure passes through the cross drilled passageways H4, to exert pressure on the left-hand end of the valve piston I39 substantially equal to the pressure exerted by the spring I33.

When the valve 4'! has been opened by the rocking arm 49 by turning the control handle 42 to an on position, fluid under pressure will enter the passageway 58, which communicates with an annular groove I39 formed in the outer periphery of the valve sleeve Iii Said valve sleeve is cross drilled from said grooved portion I39 to the inner periphery thereof, as in indicated by reference characters I48, I49, to permit fluid to pass from the passageway 58 to the valve piston Hi3 (see Figures 8 and 9).

When the valve 4!} is in the position shown in Figure 8, the spring I33 will be free and there will be a predetermined amount of clearance between the end of said spring and the seat 34. In this position of said valve, the land III will close the passage of fluid to the control line 44 and there will be no pressure in said control line. As the control handle 42 is turned in a direction, which in Figure 3 is a clockwise direction, the valve ll is first opened to admit fluid to the valve piston IE5, as has been mentioned before. The spring 133 at the same time is moved to the left into engagement with the seat I34. Continued turning of said control handle will compress said spring and cause said spring to move the piston I 38 to the left until the land H3 is moved out of lap with the corresponding land formed in the valve sleeve lIil, as is shown in Figure 9. This will admit fluid within the valve sleeve H3 and will permit fluid to pass by the land H3 into a groove i 58 formed in the valve sleeve. From thence fluid will pass in the space between the lands i it and I I2, into a groove I4I formed in said valve sleeve, into the space formed between the lands H2 and III, into a groove I42 formed within said valve sleeve, through the cross drilled passageways H4, H4 to the hollow center of said valve, and through the hollow center of said valve out through the control line 34 to the distributor valve 4|. At this time fluid will also be exerted against the left-hand end of said piston, to tend to move said piston to the right against the compression spring i153.

When the ,ressure exerted against the lefthand end of the piston IE3 is greater than the pressure exerted against said piston by the spring 33, said piston will move to the right against said spring. When said piston has been moved to the right a distance sufficient to move the land H8 out of lap with the inside of the valve sleeve I II), fluid will be discharged through cross drilled passageways I 13, hi3, through a groove I46 formed within the sleeve H3 in the space between the lands II 8 and I I9, through a groove 141, formed within the valve sleeve III] in the space between the lands H9 and I23, through a. groove I49 formed in said sleeve, and through passageways drilled from the inner end of said sleeve into said groove, to the hollow chamber formed in the casing 35, and out through the discharge passageway 68 to the low pressure side of the accumulator I5.

When the control handle 42 is turned to the first operating position, the spring I33 is displaced an amount equal to the travel of the operating member I 26 minus the clearance between the end of the spring and the valve seat and the clearance between said valve seat and the end of the valve cylinder III). When said spring has been displaced this amount, fluid under pressure will pass through the hollow piston I09 into the chamber leading to the control line 44, at a pressure substantially equal to the force exerted by the spring I33. This pressure is sufiicient to move the piston 96 and land 99 of the distributor valve 4| to a position to open the first port opening to fluid under pressure from the pressure line 90, to supply fluid under pressure to close the contactors I and 8 (see Figure 1). As pressure in the control line 46 tends to increase beyond the force exerted by the spring I33 and the valve required to open the first port opening in the distributor valve 4|, the valve piston I09 will be moved to the right against the spring I33 by pressure exerted against the left-hand end of said piston, to release fluid from the end of the valve sleeve III! into the hollow casing 35. As the pressure against the left-hand end of said valve piston is reduced, said spring I33 will move said valve piston to the left a distance suflicient to close the passage of fluid from the passageway 58 to the line 44. If the pressure tends to be reduced below the value required to hold said distributor valve open at the first port opening, said spring will move said piston a distance sufficient to admit fluid under pressure past the lands III, H2 and I I3, to the control line 44.

It should here be understood that in order to maintain the desired pressure in the control line 44 and take care of any leakages of fluid, the piston I69 is continually moving back and forth in the valve sleeve I II), to hold pressure in the line 44 and admit fluid under pressure to said line, or to discharge fluid from the end of the sleeve H6 to the hollow inside of the casing 35 and to the return through the passageway 68.

As the displacement of the spring I33 is increased by turning of the control handle 42 in a clockwise or on direction, the pressureof the fluid entering the control line 44 wi11 be correspondingly increased. Thus a definite pressure will be supplied to the distributor valve 4! for each notch on the notching cam 55, which pressures progressively increase step by step, to successively open the port openings in the distributor valve 4| to the passageways I03, I04, I35, I38, I31 and I08. When all of the passageways I93 to I38 inclusive are opened, all of the contacts I to 8 will be closed. and the motors I9, I3 will be in a full speed running position.

As the control handle 42 is turned in an opposite direction, the displacement of the spring I33 will be decreased for each step on the notching cam 55 and fluid pressure exerted against the left-hand end of the valve piston I09 will move said valve piston to the right. This will permit fluid to be discharged through the return passageway 68, until said valvepiston has been bal- 'anced and the desired pressure has been established in a control 46 for the corresponding position of the control handle 42, so the contactors 'I to 8 will open in a predetermined order.

Referring now in particular to the relief valve 45'which forms an overload relay for the electrical system, said relief valve, as herein shown, includes a valve piston I53 slidably mounted in a chamber I54 formed in a valve block I55. A compression spring I56 encircles a reduced end I51 of said valve piston and abuts the end of a land I59 of said piston. The opposite end of said spring abuts the closed end of a threaded sleeve I63, threaded within an enlarged drill hole formed in the end of said valve block, concentric with the chamber I54. A nut I6I and threaded cap piece I62 are provided to lock said threaded sleeve in position and to hold said spring to the desired tension.

The opposite end of the valve piston I53 abuts an armature I 63 slidably mounted in a sleeve I64, secured to and extending outwardly from the valve block I55, concentric with the chamber I54. Said armature is encircled by a shunt coil I65 and a series coil I66, spaced outwardly from said shunt coil. Said shunt coil serves as a holdout .coil, to hold said relay in a discharge position until the power circuit is interrupted, and is shown in Figure 1 as being connected with a switch I69. which is connected with a positive conductor I16 of a main power line.

The series coil I66 is connected in series with the main line circuit leading to the motors I6, I 0, and serves to move said armature in a direction, which in Figures 11 and 12 is shown as being to the left, upon a predetermined load on the motor circuit. It should here be inderstood that the shunt coil I65 is connected in the motor circuit when the switch I69 is closed, and that said coil serves onlyas a holdout coil, to hold the valve in a discharge position, when it has been opened by the series coil, due to a predetermined load on the motors I6, I 6. When it is desired to reset the relay, the switch I69 is opened to interrupt the power circuit to the shunt coil I65. The spring I56will then return the valve piston I53 to a position to permitfluid under pressure to flow through said release valve from the control line 44 to the control line 46. Said switch is then closed to supply power to said shunt coil, it being understood that said shunt coil is not strong enough to'actuate the armature I63 or to hold said armature from operation by the series coil I66.

"I, intermediate its ends,-which serves to close the passage offluid from a passageway I12 to a passageway I13. Said last mentioned passageway is connected with a pipe I 14 leading to the return through the valve casing 35, passageway 66, and return pipe 34. The passageway I12 is connected with the pipe 46 leading to the distributor valve 4|. Fluid under pressure enters the valve 45 through the pipe I15 leading to the chamber of said valve. Drain passageways I16 and I1! are provided in said valve block and are connected with opposite ends of the chamber I54, to return any fluid which might leakby either end of said valve piston to the low pressure or tank side of the accumulator I5.

When the relief valve 45 is in the position shown in Figures 11 and 12, fluid under pressure from the variable pressure control valve 46 enters said valve through the pipe 44 and passage- The valve piston I53 is provided with a land 44 connected with a passageway I 12 way I15; It then passes through the valve chamber I54, and out the passageway I12 and pipe 46, to the distributor valve lI.

When, however, the motors it, It are overloaded, the series coil I66 will move the armature I63 to the left. This will move the valve piston I53 to the left and will move the land H! to a position to close the passage of fluid from the passageway I15 to the passageway I12, and to allow fluid to flow from the passageway I12 to the passageway I13, out the pipe I14, to return to the low pressure or tank side of the accumulator I5.

Upon the release of fluid under pressure from the line 46, when all of the ports in the distributor valve 4I leading to the pipes N33 to I53 inclusive are opened, the spring till will move the piston 66 in a direction, which in Figure 1 is shown as being towards the left, to successively close each port opening leading to each of said pipes, one by one, and permit fluid from said pipes to return to the tank through the drain Iili Said spring serves to move the piston 36 to the left, to successively open the pipes I63, I61, I66, I 05, I64 and I 63 to the return through the drain NH, and permit each associated contactor to open in a predetermined order. Said spring also tends to force fluid from the left-hand end of said distributor valve into the pipe 46 through the valve 45, to the return.

It may be seen from the foregoing that upon a predetermined load on the motors i6, I6, fluid will be released from the pressure line 46 and the contactors controlled by said distributor valve will be opened in a predetermined order. It may also be seen that the arrangement of this valve and the connection of this valve in the fluid system is such as to prevent all of the contactors from opening at the same time, upon overload of the motor circuit, and thus prevent excessive arcing and burning of the contacts.

While I have herein shown and described one form in which my invention may be embodied, it will be understood that the construction thereof and the arrangement of the various parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be construed as limiting my invention to the speciflc embodiment illustrated, excepting as it may be limited in the appended claims.

I claim as my invention:

1. In a fluid operating system, a plurality of fluid motors, an electric circuit controlled by said motors, a pump, a fluid storage tank, a distributor valve, a high pressure line connecting said pump with said distributor valve, said distributorvalve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure from said high pressure line to said motors, for operating said motors in a predetermined sequence, a variable pressure control valve, a connection from said pump to said valve for supplying fluid under pressure thereto at a constant pressure, a variable pressure control line connecting said control valve With said distributor valve, for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to operate said distributor valve and cause said distributor valve to open said port openings to fluid under pressure in apredetermined sequence, and a relief valve operable upon a predetermined current load on said electric circuit and connected in saidvariable pressure control line between said variable pressure control valve and said distributor valve, for relieving pressure from said control line leading to said distributor valve, to permit said distributor valve to successively close said port openings to fluid under pressure from said high pressure line and to open said port openings to the return upon a predetermined current load on said electric circuit.

2. In a fluid operating system, a plurality of fluid motors, an electric circuit controlled by said motors, a pump, a fluid storage tank, a distributor valve, a high pressure line connecting said pump with said distributor valve, said distributor valve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure from said high pressure line to said motors, for operating said motors in a predetermined sequence, a variable pressure control valve, a connection from said pump to said valve for supplying fluid under pressure thereto at a constant pressure, a variable pressure control line connecting said control valve with said distributor Valve, for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to operate said distributor valve and cause said distributor valve to open said port openings to fluid under pressure in a predetermined sequence, and an electrically operated relief valve electrically connected with said electric circuit and connected in said variable pressure control line between said variable pressure control valve and said distributor valve, for relieving pressure from said control line leading to said distributor valve, to permit said distributor valve to successively close said port openings to fluid under pressure from said high pressure line and to open said port openings to the return upon a predetermined current load on said electric circuit.

3. In a fluid operated controller adapted to control an electric circuit, a plurality of electric contacts, a separate fluid motor for operating each of said contacts, a distributor valve for supplying fluid under pressure to said motors in a predetermined sequence, a. variable pressure control valve for supplying fluid under pressure to said distributor valve, to cause said distributor valve to progressively open and successively supply fluid under pressure to said motors, and an electrically operated fluid relief valve, electrically connected with the electrical circuit, for by-passing pressure from said variable pressur control valve, upon a predetermined current load on said electric circuit.

4. In a fluid operated controller adapted to control an electric circuit, a plurality of electric contacts, a separate fluid motor for operating each of said contacts in a definite order, a distributor valve for supplying fluid under pressure to said motors in a predetermined order, a variable pressure control valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open and supply fluid under pressure to said fluid pressure operating means, and an electrically 'operated fluid relief valve, electrically connected with said electrical circuit, and connected in the line from said variable pressure control valve to said distributor valve, for by-passin pressure between said variable pressure control Valve and said distributor valve upon a predetermined current load on said electrical circuit.

5. In a fluid operated controller adapted to (iii control an electric circuit, a plurality of contacts for making and breaking an electric circuit, a separate fluid motor for operating each of said contacts in a definite order, a distributor valve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure to said motors in a predetermined order, a variable pressure control valve, 3, pressure line connecting said variable pressure control valve to said distributor valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open said port openings to fluid under pressure, and an electrically operated fluid relief valve connected in said pressure line to relieve pressure from said pressure line upon a predetermined current load on said electric circuit.

'6. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for making and breaking an electric circuit, a separate fluid motor for operating each of said contacts in a definite order, a distributor valve having a plurality of port openings therein, each of said port openings bein connected with One of said motors for supplying fluid under pressure to said motors in apredetermined order, a variable pressure control valve, 9, pressure line connecting said variable pressure control valve to said distributor valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open said port openings to fluid under pressure, an electrically operated fluid relief valve connected in said pressure line and electrical means for operating said valve, and electrical connections from said electric circuit to said relief valve to cause said valve to block the passage of fluid from said variable pressure control valve to said distributor valve and to release fluid pressure from said pressure line connected with said distributor valve, to permit said distributor valve to progressively close said port openings to pressure and permit the release of fluid pressure from said motors.

7. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for making and breaking an electric circuit, a separate fluid motor for operating each of said contacts in a definite order, a distributor valve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure to said motors in a predetermined order, a variable pressure control valve, a pressure line connecting said variable pressure control valve to said distributor valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open said port openings to supply fluid under pressure to said fluid pressure operating means, an electrically operated fluid relief valve connected in said pressure line between said variable pressure control valve and said distributor valve, said relief valve being adapted to normally permit fluid to pass through said pressure line, but to stop the flow of fluid from said variable pressure control valve and to relieve fluid pressure from the pressure line to said distributor valve upon overload of said electric circuit, to permit said distributor valve to close said port openings to pressure and to open saidpor't openings to the return.

8. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for making and breaking an electric circuit, a separate fluid motor for operating each of said contacts in a definite sequence, a distributor valve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure to said motors in a predetermined order, a vari-, able pressure control valve, a pressure line connecting said variable pressure control valve to said distributor valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open said port openings to supply fluid under pressure to said fluid pressure operating means, and an electrically operated fluid relief valve connected in said pressure line, said relief valve being adapted to permit fluid to pass through said pressure line When in one position, but to block the flow of fluid from said variable pressure control valve and to relieve fluid pressure from said distributor valve when in another position, an armature for operating said valve, and a series coil wound concentrically with'said armature and connected in series with said electric circuit for moving said relief valve to a position to relieve fluid pressure from said distributor valve upon overload of said electric circuit, to permit said distributor valve to close said port openings to pressure, step by step, and open said port openings to the return.

9. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for making and breaking an electric circuit, a separate fluid motor for operating each of said contacts in a definite order, a distributor valve having a plurality of port openings therein, each of said port openings being connected with one of said motors for supplying fluid under pressure to said motors in a predetermined order, a variable pressure control valve, a pressure line connecting said variable pressure control valve to said distributor Valve for supplying fluid under pressure to said distributor valve at pressures progressively increasing step by step, to cause said distributor valve to progressively open said port openings to supply fluid under pressure to said fluid motors in a definite sequence, an electrically operated fluid relief valve connected in said pressure line, said relief valve being adapted to permit fluid to pass through said pressure line when in one position, but to block the flow of fluid from said variable pressure control valve and to relieve fluid pressure from said distributor valve when in another position, an armature for operating said valve, a series coil Wound concentrically with said armature and connected in series with said electric circuit for moving said relief valve to a position to relieve pressure from said distributor valve and permit said distributor valve to close said port openings to pressure step by step, and to open said port openings to the return upon a predetermined current load on said electric circuit, and a shunt coil wound concentrically with said armature and adapted to hold said valve in a closed position until said valve is manually reset by manually breaking the circuit to said shunt coil.

10. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for cutting a resistance out of or into said electric circuit step by step, a separate fluid motor connected with each of said contacts, a distributor valve for supplying fluid under pressure to said motors in a predetermined order for operating each of said contacts in a definite sequence, said distributor valve including a valve piston and having a plurality of port openings, each of said port openings being connected with one of said motors, a variable pressure control valve for supplying fluid under pressure to said distributor valve at progressively increasing pressures, to move said distributor valve piston to uncover said port openings to fluid under pressure step by step, a spring for moving said distributor valve piston in a direction to close said port openings to fluid under pressure and to open said port openings to the return, an electrically operated fluid relief valve, a pressure line connecting said variable pressure control valve With said fluid relief valve, a pressure line connecting said fluid relief valve to said distributor valve, and means connected in said electrical circuit for closing said fluid relief valve to pressure from said pressure control valve and opening said valve to permit fluid in said. pressure line connecting said relief valve to said distributor valve, to flow to the return, and to perm t said distributor valve spring to move said piston in a direction to progressively close said port openings to pressure, and to open said port openings to the return.

11. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for cutting a resistance out of or into said electric circuit step by step, a separate fluid motor operatively connected with each of said contacts for operating each of said contacts in a definite sequence, a distributor valve for supplyin fluid under pressure to said motors in a predetermined order, said distributor valve including a valve piston and having a plurality of port openings, each of said port openings being connected With one of said motors, a variable pressure control valve for supplying iluid under pressure to said distributor valve at progressively increasing pressures, to move said distributor valve piston to uncover said port openings to fluid under pressure step by step, a spring for moving said distributor valve piston in a direction to close said port openings to fluid under pressure and to open said port openings to the return, an electrically operated fluid relief valve, a pressure line connecting said variable pressure control valve with said fluid relief valve, a pressure line connecting said fluid relief valve to said distributor valve, and means connected in said electrical circuit for closing said fluid relief valve to pressure from said pressure control valve and opening said valve to permit fluid in said pressure line connecting said relief valve to said distributor valve, to flow to the return, and to permit said distributor valve spring to move said distributor valve piston in a direction to progressively close said port openings to pressure and to connect said port openings to the return, including an armature operatively connected with said relief valve and a series coil wound concentrically with said armature and connected in series with said electric circuit, for operating said relief valve upon overload of said electric circuit.

12. In a fluid operated controller adapted to control an electric circuit, a plurality of contacts for-cutting a resistance out of or into said electric circuit step by step, a separate fluid motor operatively connected with each of said contacts, for operating each of said contacts in a definite sequence, a distributor valve for supplying fluid under pressure to said motors in a predetermined order, said distributor valve including a piston,

17 a plurality of port openings, each of said port penings being connected with one of said motors, a variable pressure control valve for supplyin fluid under pressure to said distributor valve at progressively increasing pressures, to move said distributor valve piston to uncover said port openings to fluid under pressure step by step, a spring for moving said distributor valve piston in a direction to close said port openings to fluid under pressure and to open said port openings to the return, an electrically operated fluid relief valve, a pressure line connecting said variable pressure control valve with said fluid relief valve, a pressure line connecting said fluid relief valve to said distributor valve, means connected in said electrical circuit for closing said fluid relief valve to pressure from said pressure control valve and opening said valve to permit fluid in said pressure line connecting said relief valve to said distributor valve, to flow to the return, and to permit said distributor valve spring to move said distributor valve piston in a direction to progressively close said port openings to 1% pressure and to connect said port openings to the return, including an armature operatively connected with said relief valve, a series coil wound concentrically with said armature and connected in series with said electric circuit, for operating said relief valve upon overload of said electric circuit, and a shunt coil wound concentrically with said armature and adapted to hold said valve in a closed position until said valve is reset manually by interrupting the circuit to said shunt coil under manual control.

JOSEPH J. SLOMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,102,294 Taliaferro et a1 Dec. 14, 1937 2,259,809 Freeman Oct. 21, 1941 2,136,921 Joy Nov. 15, 1938 2,383,894 Sloane Aug. 28, 1945 

